Hey fellow drive gurus, I have one that I have never come across before. I have a client wanting to use an 40HP (30kW) 460V induction motor on a water turbine pump and have the water overhaul it to turn it into an induction generator. So far so good, I’ve done that before. But the new twist is...
I have never worked outside of North America, but I was under the impression that we are, for the most part, the only ones who use delta power distribution systems, that "everywhere else they use wye (star) distribution"; in quotes because a former boss from England made that statement to me...
Yes, that’s what is reported in this article.
https://oilprice.com/Energy/Energy-General/Tech-Breakthrough-Could-Help-Slumping-Electric-Car-Sales.html#
Given that the source is a publication for oil traders, I’m skeptical that this might be a planted story meant to raise hopes, so that they...
Has anyone heard of two different types of GEAR being "series rated"? A claim was made by a salesperson for a company that makes MCCs and Switchgear that the must be given the order for both because the MCCs are "series rated" at 100kA with the switchgear. The data sheets for the MCCs clearly...
Can anyone share some shortcuts to estimating inertia on older machines for which drawings and data sheets are not available? I need to come up with a replacement braking system for older candler roller machines and the machine mfr is long gone. My fall back position is that since it starts...
Just checking to see if anyone else has run into this. I have a customer who has a 200HP VFD on a submersible pump. 1/4 mile away is another station that has pressure transducers. Whenever the VFD is running, the pressure transducers go haywire. It's been thoroughly vetted, the link is...
Has anyone bought a 5kV 200-400A (or so) ATS recently, as in the last year or so? I haven't bought one in over 10 years. I just need a rough order of magnitude (aka "hand grenade" price) to plug into a comparison on a project, nothing fancy, no spec. In fact my contention is that they don't need...
I'm being asked to bid on a project that involves retrofitting a Medium Voltage VFD into an existing facility that has a MV MCC in place already, and there is no space in the room to fit the MV VFD in it's entirety. The VFD is a VSI drive with an 18 pulse front-end, so it has a large transformer...
This is a new one on me. Someone called wanting my help on figuring out why they have had 3 failures of Line Reactors ahead of some 40HP VFDs. 30 years in this industry and I have never once seen a line reactor fail. It's too stupid of a device; wire and iron. What could fail? So far no details...
I'm looking for a way to supply roughly 75A, 650VDC (to a VFD DC Bus) from a 240VAC single phase source, without a transformer. I'm doing it with a transformer now, the problem is the size and weight (>500 lbs) for the machine OEM, as it is for the transportation industry and everything heavy...
I have someone wanting to use an AC motor on a vacuum furnace which uses argon as a quenching gas, the motors are on fans used to evacuate the gas after the cooling cycle. There is an NFPA regulation for these systems, NFPA 86, which dictates that motor windings that are exposed to argon (or...
I have been heavily promoting the use of VFD shielded power cable in my installations, and most of the problems I have experienced in the past have been diminishing to near extinction. But today, I went to a site with MULTIPLE motor failures connected to a VFD system that I designed, but was...
Believe it or not, I am being asked to defend the use of VFDs for a large pumping project where the technology being considered is actually Eddy Current Clutches! I have not run into this idea for years. They currently have them on about 1/2 of their systems, the other half are (our) VFDs. The...
Today's challenge for the graybeards:
I must come up with a way to interface a new AC vector drive system (for a hoist) to an existing control cab for a GE DC M-G set drive system that was 50+ years old. The customer is insisting on retaining the existing operator control system that he says is...
Well written article that I thought worthy of sharing with those who don't peruse this site provider, Drives and Controls UK magazine. I hope the direct link works.
http://www.drives.co.uk/features.asp?id=3
"Dear future generations: Please accept our apologies. We were rolling drunk on...
I've been in this business 30+ years, yet today I heard this for the very first time from a customer wanting me to help him specify a VFD. He has an 18 pole 200HP AC SCIM and all the time we were talking, he kept want me to assure him that I understood that "this is a high saturation motor, it's...
This one has me scratching my head, but I figure the group consciousness will hold the necessary experience for a forensic evaluation from afar. Don't let me down... [wink]
We have a 3 phase 480/277V Y-Y PT in an MCC, 4:1 ratio feeding a Multilin PQM. It's been sitting for 4 years not...
I'm going out to a mine in Arizona tomorrow to discuss a couple of projects we are working on, and yesterday one of our salesmen told me that at this mine, they have a very old motor that he referred to as a "Tesla Motor", apparently built by old man Nick hisself. He said he was told it is one...
I'm looking for opinions or even standards I am unaware of on this issue.
I am being asked to move the CTs for a power monitor to the LINE side of a 600A main fused disconnect switch of an MCC. This is a non standard configuration for us and requires significant re-engineering, something I'd...
In a project I am working on, the end user has requested that we integrate Yaskawa AC7 "matrix converters" as a regenerative AC drive, as opposed to PWM based regenerative VFD offerrings. I have plenty of experience with Yaskawa products and have no lack of confidence in them, but I have never...
